CN1249935C - Cyclic cell search - Google Patents

Abstract

A wireless communication system which comprises a plurality of base stations and a user equipment. Each base station transmits a common primary synchronization code (PSC) in a primary synchronization channel at a different timing within a system frame, and a midable code in a broadcast channel. A transmitted power level of the PSC and a midable code are at a common fixed ratio for each base station. The user equipment (UE) is capable of conducting cell search and includes a receiver for receiving said PSCs, a signal power measuring device for measuring the power level of received PSCs and identifying a frame timing of received PSCs which exceed a power threshold, and a processor for analyzing data signals received in the primary synchronization channel associated with the PSC with the highest power level of the received PSCs with a threshold exceeding power level. The processor also synchronizes or maintains synchronization with the base station associated with the highest PSC, the data signals including secondary synchronization codes.

Description

Periodic Cell Search

technical field

The present invention relates to wireless communication systems. More specifically, the present invention relates to cell search in a time division duplex communication system using code division multiple access. This application claims priority from the following patent applications: US Provisional Patent Application No. 60/223,405, filed August 4, 2000, and US Provisional Patent Application No. 60/230,123, filed September 5, 2000.

Background technique

Cell search is a process in which a wireless user, user equipment (UE 10), is synchronized with a base station of a cell before transmitting traffic data (eg voice data). Figure 1 illustrates a UE 10 in a wireless communication system. After activation, UE 10 does not know its location. UE 10 selects a cell 12 ₁ among multiple cells 12 ₁ to 12 _n (12), and communicates with its associated base station 14 ₁ . Before commencing communication, the UE 10 and the selected base station ₁₄₁ are synchronized in terms of timing and code settings.

The cell search process consists of three steps. In a first step (step 1 ), the UE 10 identifies nearby base stations 14 ₁ to 14 _n (14). Each base station 14 transmits a primary synchronization code (PSC) on a primary synchronization channel PSCH.

In a typical Time Division Duplex (TDD) communication system using Code Division Multiple Access (CDMA), the PSCH resides in one of the fifteen slot frames in one case (i.e., the aforementioned case one) time slot, or in another case (i.e. the aforementioned case 2) resides in two time slots therein. In case one, the PSCH is transmitted in one slot K out of fifteen slots. In case two, PSCH is transmitted in one of two time slots K and K+8. In order to distinguish between different base stations 14, each base station 14 transmits its PSC from the slot boundary according to a particular time offset, _tOFFSET , in the PSCH.

In step 1, the UE 10 looks for the transmitted PSC from the base station 14. The UE 10 observes one or two PSCH slots in order to discover the received PSC. Since the PSC is typically unmodulated, eg an unmodulated 256 chips, the search can be done by looking for the peak of a matched filter output over the time slot. Each peak is a potential candidate base station 14 to be synchronized.

In step 2, information about each cell is determined, such as the code placement of the cell, t _OFFSET , the frame index number within the interleaving period of two frames, and the time slot of the PSC through which the cell transmits (for case 2) . To determine the information for each cell, the UE 10 looks for a Secondary Synchronization Code (SSC) transmitted along each PSC. On each peak, the UE 10 searches for transmitted SSCs. SSC may be modulated with data. Based on the SSC detected by each base station and the modulated data, UE 10 can determine cell information.

In step 3, the UE 10 determines the base station 14 ₁ to be synchronized. For this determination, the UE 10 monitors the Broadcast Channel (BCH) of the Primary Common Control Physical Channel (P-CCPCH) for the transmitted training sequence codes for each potential base station 14 requiring synchronization. The base station ₁₄₁ having the midamble code with the highest received power is selected as the base station 14 for synchronization.

To implement this cell search procedure, there is a tradeoff between complexity and synchronization time. To speed up synchronization, a matched filter that finds all inconsistent cell SSCs and midamble codes can be used. An alternative approach is to use fewer reconfigurable matched filters over multiple frames. Using multiple frames increases synchronization time but reduces the number of matched filters and other cell search components.

Therefore, a better approach is to take an alternate approach for cell search.

Contents of the invention

A wireless communication system including multiple base stations and a user equipment. Each base station transmits a common primary synchronization code (PSC) in a primary synchronization channel PSCH according to different timings in a system frame, and transmits a training sequence code in a broadcast channel. The transmitted power level and midamble code of a PSC are at a common fixed ratio for each of said base stations. A user equipment (UE) capable of cell search and comprising a receiver for receiving said PSC, a receiver for measuring received PSC power levels and for identifying received PSCs exceeding a power threshold A frame timing signal power measuring device and a processor for analyzing data signals received in the Primary Synchronization Channel PSCH associated with the PSC with the highest power level among the received PSCs exceeding the power level threshold. The processor is also configured to synchronize or synchronize said data signal with the base station associated with said highest PSC, the data signal comprising a secondary synchronization code.

In other words, the present invention provides a user equipment UE capable of performing cell search in a wireless communication system with multiple base stations, where each base station transmits a common Primary synchronization code PSC, and transmit a training sequence code in a broadcast channel, wherein the transmission power level ratio of a primary synchronization code and training sequence code remains fixed for each of the base stations, the user equipment includes:

a receiver for receiving said master synchronization code;

a signal power measuring device for measuring the received PSC power level and for identifying a frame timing of received PSCs exceeding a power threshold; and

a processor configured to analyze data signals received in the Primary Synchronization Channel PSCH associated with a Primary Synchronization Code with the highest power level among received Primary Synchronization Codes exceeding a power level threshold, and configured to and synchronizing said data signals with or with a base station associated with said primary synchronization code having the highest power level, the data signals comprising a secondary synchronization code.

The present invention also provides a wireless communication system comprising:

A plurality of base stations, wherein each base station transmits a common primary synchronization code PSC in a primary synchronization channel PSCH according to different timings in a system frame, and transmits a training sequence code in a broadcast channel, wherein a primary synchronization code and the transmission power level ratio of the midamble code remains fixed for each of said base stations; and

A user equipment UE capable of cell search, including:

a receiver for receiving said master synchronization code;

a signal power measuring device for measuring the received PSC power level and identifying a frame timing of received PSCs exceeding a power threshold; and

a processor configured to analyze data signals received in the Primary Synchronization Channel PSCH associated with a Primary Synchronization Code with the highest power level among received Primary Synchronization Codes exceeding a power level threshold, and configured to and synchronizing or maintaining synchronization with the base station associated with said primary synchronization code having said highest power level on said data signal, said data signal comprising a secondary synchronization code.

The present invention further provides a method for cell search in a wireless communication system having multiple base stations and a user equipment UE, the method comprising:

Each base station in the plurality of base stations:

transmit a common primary synchronization code PSC in a primary synchronization channel PSCH according to a different timing in a frame; and

transmitting a midamble in a broadcast channel, wherein a transmission power level ratio of a primary synchronization code and midamble remains fixed for each of said base stations; and

On the user device side:

receiving the master synchronization code;

Measuring the received PSC power level;

identifying a frame sequence having the highest power level of the received primary synchronization code that exceeds a power threshold;

analyzing a data signal received in a primary synchronization channel for a primary synchronization code that exceeds a power level threshold, wherein the data signal includes a secondary synchronization code; and

and synchronizing said data signal to or with a base station associated with said primary synchronization code having the highest power level.

The present invention also provides a method for time synchronization processing of a plurality of base stations and a user equipment in a wireless communication system, the system has a plurality of base stations, which transmit a primary synchronization code PSC in a primary synchronization channel PSCH, Wherein the primary synchronization code of each base station is transmitted in a different timing in a system frame, a training sequence code transmitted in a broadcast channel, the training sequence code and the transmission power level of the primary synchronization code For each of said base stations at the same fixed ratio, said method comprises the following steps:

On the user device side:

receiving said primary synchronization code for each of said plurality of base stations;

measuring a power level of the received primary synchronization code;

detecting a frame timing of said primary synchronization code whose power level exceeds a power threshold;

identifying base stations related to the primary synchronization code exceeding the power threshold, and extracting base station information including a time offset and a time slot of one of the identified base stations;

adjusting frame timing of the primary synchronization code of the identified base station for the time offset;

calculating a time of arrival TOA for each of said adjusted frame timings of the primary synchronization code; and

A timing of the base station is adjusted with respect to the arrival time.

Description of drawings

FIG. 1 is a diagram of a user equipment (UE) in a wireless communication system.

Fig. 2 is a flowchart related to cell search.

Figure 3 is a simplified diagram of a base station used for cell search.

FIG. 4 is a simplified diagram of a UE initial cell search system.

Figure 5 is a graph of the output from a PSC matched filter.

FIG. 6 is a flowchart of a cell search using specified cell slot information.

Fig. 7 is a flowchart of base station synchronization using cell search information.

Detailed ways

Fig. 2 is a flowchart of cell search. FIG. 3 is a simplified diagram of a base station 14 used for cell search. Base station 14 includes a PSC generator 28 and a plurality of SSC generators and modulators ₃₀₁ to _30n (30) for generating PSC and modulated SSC and frame timing associated with base station 14 at appropriate time slots. A BCH distribution and midamble insertion means 32 generates a BCH communication burst. The BCH bursts are time-multiplexed with the appropriate midamble codes of the base station 14 in the BCH time slots. Amplifiers 34, ₃₆₁ to _36n , 38 associated with each PSC, SSC and BCH control the transmit power level of each signal. For some cell search features, the BCH and PSC transmit power levels of each base station are set at the same fixed ratio (16) in the preferred method. As a result, the ratio of BCH and PSC transmission power levels in each cell 12 is fixed, although the BCH and PSC transmission power levels may vary from cell to cell. However, for other cell search features, a fixed BCH/PSC ratio is not necessary. The amplified PSC, SSC and BCH are combined by a combiner 40 and radiated by an antenna 42 .

FIG. 4 is a simplified diagram of a cell search system for UE 10. Step 1 of the periodic cell search is performed by the step 1 means 44 . For case one of the TDD/CDMA system, the step 1 device only searches a single time slot, while for case two, it searches two time slots. Figure 3 shows one embodiment of step 1 means 44, although other embodiments may also be used. Step 1 means 44 includes a matched filter 50 , a noise estimator 52 , and a comparator 54 . An antenna 58 receives radio frequency signals. After the received signal has been demodulated from a baseband signal, eg by means of a demodulator 56, an input signal I is received and processed by a matched filter 50. Matched filter 50 is matched to the PSC. As shown in FIG. 5 , the output of the matched filter 52 will be a series of pulses representing the received PSC power levels of the cells detected by the matched filter 50 .

A noise estimator 52 coupled to matched filter 50 and comparator 54 estimates the noise power of the PSCH making up the received input signal I. A possible noise estimator 52 calculates the received power for each point. Estimator 52 then averages the noise power at these points and outputs this value to comparator 54 .

The outputs from matched filter 50 and noise estimator 52 are received by comparator 54 . Comparator 54 determines which pulses are possible cell detection results. A comparator 54 uses the estimated noise power received from estimator 52 to make this determination. The estimated noise power is used to generate a threshold, K1. The predetermined value K1 is selected on the basis of maintaining a predetermined false alarm rate for a PSC signal. One value of K1 is twice the estimated noise power (that is, 3dB above the noise power estimate), and the other value is four times the noise power (that is, six dB above the noise power estimate). ). The false alarm rate may be fixed, or determined on a basis that varies from case to case or even from UE to UE.

Comparator 54 then compares each received PSCH burst to a threshold. If the pulse is above the threshold, the comparator 54 assigns it a cell detection and outputs its position in the frame to the step 2 means 46 (18). Comparator 54 also indicates the pulse with the highest received power. If a pulse is less than the threshold, the comparator ignores the detected power level, assuming it is a spike. Returning to Figure 5, the detections labeled D1 and D2 illustrate detections above the threshold, indicated by the thick horizontal lines.

For best performance, it is recommended to keep the ratio of BCH to PSCH transmission power level fixed for each base station. As a result, the PSCH with the highest received power should correspond to the midamble code with the highest received power. Using this assumption, steps 2 and 3 can be simplified.

Since each cell is assigned a specific time offset, the process may use the detected position in the PSC frame to infer the identity of the cell. For greater confidence in the determination, or if no cell information has been used beforehand, the procedure may run to step 2. FIG. 6 is a flowchart of using detected PSCs to infer cell identity. The UE 10 knows in advance which cell is assigned a particular time offset. Based on the determined PSC time offset, the UE determines the cell information of the cell using this offset, and may skip step 2 (19), as shown in FIG. 6 . In step 3, while detecting the BCH training code, the UE 10 verifies the accuracy of its PSC detection. If the previously obtained information is incorrect, it can be assumed that either the PSC detection is a false detection or that a cell is irrelevant to the previously obtained information.

Step 2 means 46 , coupled to step 1 means 44 and step 3 means 48 , receives the input signal I and from comparator 54 the position in the frame of each detected cell. Using the location of the cell with the highest received PSC power, step 2 means 46 determines the SSC of that cell in order to determine cell information (20, 22). Step 2 can be simplified by using only one specific PSC position for each discovered PSCH. Demodulation of the SSC utilizes a known start time derived from the detected PSC. A simple correlation process run by correlator 60 can then be implemented to obtain the parameters communicated by the SSC. The demodulation process can provide a confidence level as a by-product. This level of confidence may be the relative output magnitude for the chosen SSC mode. The SSC pattern is stored by an accumulator 62 .

If the SSC determination process exceeds a confidence level, eg as determined by a determining means 64, no additional time slot information need be accumulated. The confidence level might be a threshold, such as K2. If the confidence level has not been exceeded, accumulator 62 accumulates subsequent frame information in a discontinuous manner until a confidence level is reached, or until the frame count exceeds a certain value. After reaching the confidence level, the received SSC is determined by determining means 64 . Using the detected SSCs and the data modulated on them, cell information can be determined such as code group, t _OFFSET , frame index number and time slot in which the cell transmits the PSC (for case 2). If the confidence level is not exceeded, or if the SSC is inconsistent with the allowed SSC combinations, the initial PSC detection is assumed to be a false detection, and the next PSC with the highest received power level is processed.

Using the time location from the PSC or the cell information output from step 2, step 3 means 48 determines the BCH training sequence code and primary scrambling code for that cell. The code set determined in step 2 is associated with a set of training sequence codes, for example four training sequence codes. The input signal I is correlated with each training sequence code set during the BCH, for example through matched filters 70 to _70n (70). Correlations may be accumulated by an accumulation means 72 over a predetermined number of frames. Based on the accumulated correlations, the BCH midamble code of the cell is determined by a BCH midamble code determining means 74 . Using the determined training sequence code, the scrambling code of the cell can be determined. Step 3 can also be simplified because only the potential midamble codes of one cell are searched.

Therefore, the complexity of step 3 hardware is simplified, or the processing time of step 3 is reduced. Using the cell information from step 2 and the determined scrambling code from step 3, the UE 10 communicates with the selected base station 14 (26).

In a method that can be added, cell search information can be used for timing synchronization between base stations 14 . Although the cell search procedure described above may be used for base station synchronization, other cell search methods may also be used for base station synchronization. FIG. 7 is a flowchart of base station synchronization using cell search information from UE 14.

Using a step 1 means 44, the location of the received PSC can be determined (76). Using the step 2 means 46, the SSC for each PSC and the time offset and time slot for the cell can be determined (78). Preferably, each set of SSCs passes a confidence test (80). SSC groups that fail the confidence test will be discarded. A confidence test compares the received SSC power. The SSC with the highest received power is compared with the second highest received power. If the second high power is not within the specified percentage of the first high power, then the PSC detection will be discarded.

Because the cell 12 transmits the PSC in different time slots with different time offsets, the PSC location needs to be adjusted to compensate (82). Each received cell's adjusted PSC position simulates each cell that simultaneously transmits a PSC for its own timing. For illustrative purposes, the PSC positions of the two cells are adjusted to simulate each cell transmitting a PSC at the beginning of slot 0 (with no time offset). A time of arrival (TOA) for each adjusted PSC is determined (84). The TOA information is then used to adjust base station timing (86).

One method of synchronizing base station timing uses time difference of arrival (TDOA). The TDOA between each cell pair is deterministic. Since radio waves travel at the speed of light, using the distance between the base station 14 and the UE 10 in each cell, the TDOA of the cell for the best synchronization can be determined. If the UE 10 is in a fixed location, then the UE/base station distance may be known. UE/base station distance may also be determined by geographic location. A timing error can be identified by determining the difference between the measured TDOA and the TDOA that is best synchronized. Using the timing error, the RF network controller can adjust a timing of the out-of-sync base stations 14 .

Because base station synchronization does not have to be performed simultaneously with cell search, the PSC location, time offset, and slot information for each cell can be collected over multiple frames. As a result, no additional hardware is required to run base station synchronization. Furthermore, by using signals already transmitted by each cell, such as PSC and SSC, no further use of radio frequency resources is required for base station synchronization.

Preferably, the calculation of TDOA is performed at the RF network controller, although this could also be performed at the UE 10 or Node-B. For each detected PSC, the base station information of the PSC can be determined, such as code group, t _OFFSET , frame index number, time slot of the transmitted PSC, received power and UE-related time of arrival. The arrival time of each PSC is adjusted based on its determined _tOFFSET and time slot. Time of arrival and other cell information is sent to the RF network controller to adjust base station timing.

To start UE time-of-arrival measurements, the radio frequency network controller may instruct the UE 10 to measure a specific base station 14. After the UE 10 measures the TOA of a particular base station 14, it passes the information to the RNC for synchronization of the base station 14. A designated base station 14 can be distinguished at the UE 10 side according to its associated SSC. The RNC can also instruct the UE 10 to perform TOA measurements on all its neighbors. UE 10 transmits all detected neighboring equipment information to RNC. Preferably, the UE 10 sends a confidence level with each cell information. A confidence level takes a ratio of the received power of the PSC and compares it to the received power of the SSC. If the received power levels are close, this indicates a higher detection confidence.

RNC receives cell information and generates a measurement report. The measurement report may contain measurement results from one or more UEs 10 . Confidence levels are used to weight the information for each cell. Therefore, measurements with higher confidence are weighted more heavily than measurements with lower confidence. The history of these measurements can be tracked over time and stored in reports. A Kalman filter may be used to weight the stored information used in the base station 14 synchronization process.

Claims (23)

1. A user equipment UE capable of performing cell search in a wireless communication system with multiple base stations, wherein each base station transmits a common primary synchronization code in a primary synchronization channel PSCH according to different timings within a system frame PSC, and transmit a training sequence code in a broadcast channel, wherein a transmission power level ratio of a primary synchronization code and training sequence code remains fixed for each of said base stations, the user equipment comprising: a receiver for receiving said master synchronization code; a signal power measuring device for measuring the received PSC power level and for identifying a frame timing of received PSCs exceeding a power threshold; and a processor configured to analyze data signals received in the Primary Synchronization Channel PSCH associated with a Primary Synchronization Code with the highest power level among received Primary Synchronization Codes exceeding a power level threshold, and configured to and synchronizing said data signals with or with a base station associated with said primary synchronization code having the highest power level, the data signals comprising a secondary synchronization code. 2. The user equipment according to claim 1, wherein said signal power measuring device comprises: a matched filter matched to a common primary synchronization code for measuring each primary synchronization code received from said plurality of base stations; a noise estimator for determining received noise power in each of the transmissions from said plurality of base stations; and a comparator for determining a power threshold and for comparing said measured power levels of said received primary synchronization codes having said threshold and for outputting said primary synchronization code having the highest power level The frame timing of the synchronization code. 3. The user equipment according to claim 2, wherein said processor comprises: an SSC correlator responsive to the frame timing output from said signal power measuring means for detecting said secondary synchronization code in said primary synchronization channel PSCH to identify base stations connected to the frame timing for Extract base station information including training sequence codes; and A synchronization processor responsive to said SSC correlator capable of detecting the primary scrambling code. 4. The user equipment according to claim 3, wherein said base station information further comprises a time offset, frame index number, transmitted primary synchronization code time slot, received power, and arrival time associated with the user equipment time. 5. The UE according to claim 1, wherein said processor detects a primary scrambling code associated with a received primary synchronization code exceeding a power level threshold, and synchronizes or makes said signal maintaining synchronization with the base station associated with one of said primary synchronization codes exceeding a power threshold such that the received power level of the midamble code associated with said one of said primary synchronization codes is between said power threshold The ratio exceeds the ratio of the transmission power levels of the primary synchronization code and the midamble code. 6. The user equipment according to claim 2, wherein the base station cell information related to the primary synchronization code with the highest power level is known to the user equipment based on the frame timing, The cell information of the base station is used to extract the training sequence code. 7. The user equipment according to claim 6, wherein said processor is synchronized to a base station associated with said PSC having the highest power level. 8. The user equipment according to claim 7, wherein said base station information further comprises a time offset, frame index number, transmitted primary synchronization code time slot, received power, and arrival time associated with the user equipment time. 9. A wireless communication system comprising: A plurality of base stations, wherein each base station transmits a common primary synchronization code PSC in a primary synchronization channel PSCH according to different timings in a system frame, and transmits a training sequence code in a broadcast channel, wherein a primary synchronization code and the transmission power level ratio of the midamble code remains fixed for each of said base stations; and A user equipment UE capable of cell search, including: a receiver for receiving said master synchronization code; a signal power measuring device for measuring the received PSC power level and identifying a frame timing of received PSCs exceeding a power threshold; and a processor configured to analyze data signals received in the Primary Synchronization Channel PSCH associated with a Primary Synchronization Code with the highest power level among received Primary Synchronization Codes exceeding a power level threshold, and configured to and synchronizing or maintaining synchronization with the base station associated with said primary synchronization code having said highest power level on said data signal, said data signal comprising a secondary synchronization code. 10. The system according to claim 9, wherein said signal power measuring device comprises: a matched filter matched to a common primary synchronization code for measuring each primary synchronization code received from said plurality of base stations; a noise estimator for determining received noise power in each of the transmissions from said plurality of base stations; and a comparator for determining a power threshold and for comparing said measured power levels of said received primary synchronization codes having said threshold and for outputting said primary synchronization code having the highest power level The frame timing of the synchronization code. 11. The system of claim 10, wherein said processor comprises: an SSC correlator responsive to the frame timing output from said signal power measuring means for detecting said secondary synchronization code in said primary synchronization channel PSCH to identify base stations connected to the frame timing for Extract base station information including training sequence codes; and A synchronization processor responsive to said SSC correlator capable of detecting the primary scrambling code. 12. The system according to claim 11, wherein said base station information further comprises a time offset, frame index number, transmitted primary synchronization code time slot, received power, and time of arrival associated with user equipment . 13. The system according to claim 9, wherein said signal power measuring device extracts base station information including training sequence code; the processor detects a primary scrambling code associated with a received primary synchronization code exceeding a power threshold; and synchronizing said signal to or with a base station associated with said one of said primary synchronization codes exceeding a power threshold such that the received power of the midamble code associated with said one of said primary synchronization codes The ratio between the level and the power threshold exceeds the transmission power level ratio of the primary synchronization code and the midamble code. 14. The system according to claim 9, wherein said signal power measuring device comprises: a matched filter matched to a common primary synchronization code for measuring each primary synchronization code received from said plurality of base stations; a noise estimator configured to determine said power threshold based on noise power received in each transmission from said plurality of base stations; and a comparator for comparing said measured power levels of said received PSCs having said threshold and for outputting frame timings of identified PSCs exceeding the power threshold. 15. The system according to claim 14, wherein the base station cell information related to the received primary synchronization code exceeding the power threshold is known to the user equipment based on said frame timing, said The cell information of the base station is used to extract the training sequence code. 16. The system of claim 15, wherein said user equipment is synchronized with a base station associated with a highest power level of one of said primary synchronization codes exceeding a power threshold. 17. A method of cell search in a wireless communication system having a plurality of base stations and a user equipment UE, the method comprising: Each base station in the plurality of base stations: transmit a common primary synchronization code PSC in a primary synchronization channel PSCH according to a different timing in a frame; and transmitting a midamble in a broadcast channel, wherein a transmission power level ratio of a primary synchronization code and midamble remains fixed for each of said base stations; and On the user device side: receiving the master synchronization code; Measuring the received PSC power level; identifying a frame sequence having the highest power level of the received primary synchronization code that exceeds a power threshold; analyzing a data signal received in a primary synchronization channel for a primary synchronization code that exceeds a power level threshold, wherein the data signal includes a secondary synchronization code; and and synchronizing said data signal to or with a base station associated with said primary synchronization code having the highest power level. 18. The method of claim 17, further comprising the steps of: determining said power threshold based on noise power received in each transmission from said plurality of base stations; comparing said measured power levels of said received Primary Synchronization Codes having said threshold value, and outputting the frame timing of said Primary Synchronization Code having the highest power level; Detecting the secondary synchronization code in the primary synchronization channel PSCH, so as to identify the base station related to the frame timing, for extracting the base station information including the training sequence code; and A primary scrambling code is detected. 19. The method of claim 18, wherein said base station information includes a time offset, frame index number, transmitted PSC time slot, received power, and time of arrival associated with the user equipment. 20. The method of claim 17, wherein a ratio between a received power level of a midamble code associated with one of said primary synchronization codes and said power threshold exceeds said primary synchronization code and the transmission power level ratio of the training sequence code. 21. A method for performing time synchronization processing on a plurality of base stations and a user equipment in a wireless communication system, the system has a plurality of base stations, and they transmit a primary synchronization code PSC in a primary synchronization channel PSCH, wherein each The primary synchronization code of the base station is transmitted in a different timing in a system frame, a training sequence code is transmitted in a broadcast channel, and the transmission power level of the training sequence code and the primary synchronization code is for each The base stations are all at the same fixed ratio, and the method comprises the following steps: On the user device side: receiving said primary synchronization code for each of said plurality of base stations; measuring a power level of the received primary synchronization code; detecting a frame timing of said primary synchronization code whose power level exceeds a power threshold; identifying base stations related to the primary synchronization code exceeding the power threshold, and extracting base station information including a time offset and a time slot of one of the identified base stations; adjusting frame timing of the primary synchronization code of the identified base station for the time offset; calculating a time of arrival TOA for each of said adjusted frame timings of the primary synchronization code; and A timing of the base station is adjusted with respect to the arrival time. 22. The method of claim 21, wherein the method of identifying a base station comprises the steps of: detecting a secondary synchronization code SSC in said primary synchronization channel PSCH; and A confidence test is performed on the SSC. 23. The method of claim 22, wherein adjusting said frame timing for said arrival time comprises the steps of: calculating a time difference of arrival TDOA for each of said identified base stations using the time of arrival; comparing said calculated time difference of arrival TDOA with the stored time difference of arrival TDOA; and A timing error is generated based on the comparison.

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